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(No Model.)

2 Sheets-Sheet T. THRELFALL.

ROCK DRILLING MAGHINE.

No. 282,687. Patented Aug. 7, 188s.

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(No Model.)

. 2 Sheets-Sheet 2. T. THRBLFALL. y

l ROCK DRILLING MACHINE.,

Patented Aug. '7, 1883.

y mw www MW V OMS/@MMV UNITED STATES PATENT EEICE.

THOMAS THRELFALL, OF SAN FRANCISCO, CALIFORNIA, ASSIGEOR TO JAMESVATSON, OF SAME PLACE. I

ROCK-DRILLING MACHINE.

SPECIFICATION forming part of Letters PatenNo. 282,687, dated August 7,1883,

`Application filed February 2, 1882. Renewed June 7, 1883. (No model.)

To all whomjt may concern.-

Be it known that I, THOMAS THRELEALL, a subject of the Queen of GreatBritain, and residing at San'Francisco, in the county of San Franciscoand State of California, have invented certain new and usefulImprovements in Rock-Drilling Machines, of which the following is aspecification.

My invention relates to improvements in rock-drilling machines which maybe operated by hand or other motivepower; and the objectsofmyimprovements are, first, toprovidearockdrilling machine in which thehammer which drives the drill is actuated by an expansive springcontained within the general outlines of the frame-work of the saidmachine; second, to provideanew and improved 1n eans whereby the drillmay be automatically and partially rotated at the end of each stroke;third, to provide a new and improved means whereby the drill may bewithdrawn from the face of the rock, partially rotated, and then pressedagainst the face of the rock preparatory to receiving the next blow fromthe hammer; fourth, to 4provide a means whereby the drill and itsactuating mechanism may be fed forward as the work progresses; iifth, toprovide a means whereby the withdrawal of the drill from the face of therock, rotation, and advancement of the drill to the rock-face, and blowof the hammer are given in a regular and successive manner 5 sixth, toprovide an improved arrangement of the gearing and cams for driving thedrilling mechanism. I attain these obj ects by the mech.

anism illustrated in the accompanying drawings, in which- Figure l is aside elevation of the machine, showing the position of the partsimmediately after the blow has been struck. Fig. 2 is a cross-sectionalview on line X X of Fig. l. Fig. 3 is a cross-sectional view on line X Yof Fig. 1. Fig. 4 is a side view of Fig. 3. Fig. 5 is a cross-sectionalview on line Y Y of Fig. l. Fig. 6 is a cross-sectional view on line Z Zof Fig. l, (omitting the at spring.) Fig. 7 is a perspective view,partly broken away, of the lower or stationary bed-plate.

Similar letters of reference are used to designate like parts throughoutthe several views.

The bed-plate A of my drill is mounted upon a tripod or other similardevice, having means for horizontal, vertical, and angular adjustment,and the legs of which are adjustable, to provide for the inequalities ofthe surface of the ground upon which the drill is placed. The upperbed-plate, B, is supported by and moves upon the bed-plate A, and isheld in position by means of the dovetail C. The drill is fed forward orretracted by revolving the screw or feed rod D, one end of which passesthrough the threaded nut or cross-bar E, formed across the top of thebed-plate A, which is hollowed out to admit of the passage of saidscrewrod, while the other end is provided with a collar, F, for takingup the thrust of said rod, and passes through the lug G, formed upon therear outer end of the upper or movable bed-plate, and is providedwiththe crank-handle H, by which the rod is revolved and the upper plate andthe operating mechanism moved forward or backward upon the lowerbed-plate, A.

rIhe drill-stock I is formed of a solid piece of metal, having its frontend perforated to receive the drill, and is provided with any suitableclamping devi ce for holding the drill firmly within its socket. It islikewise provided with a longitudinal groove, J, extending from thefront end to a short distance from the rear end.

The drill-stock is supported and held in position by the two standards Kand L, erected upon the bed-plate B, and they are each provided with ahinged cap, M. (Seen inside elevation in Fig. 3.) The upper outer end ofthe standard is slotted or provided with two lugs, N N,

between which is pivoted a bolt, O, whvich rests between twocorresponding lugs upon the cap M, hinged to the opposite side of thestandard. When the drill-stock has been placed in position, the caps arethrown down and bolt O y turned up between the4 lugs. The nut I isturned down and clamps the cap firmly to place. About midway between thetwo standards are placed the two collars 'Q It, adjustably securedthereto by set-screws. Between the collars is placed the yoke S, whichis adjustably secured upon the rod T. The rod T passes throughperforations made in the standards K L, and a coiled spring, U,is placedaround it between the standard L and the baseof the yoke S. Upon theface of the standard L, I fasten the strap-irons V V, which hold inplace the rod W', the upper end of which is slotted to receive the pawlX and spring Y. A coiled spring, Z, is placed around the last-named rod,and rests upon the lower strap-iron V, while the upper end pressesagainst a pin set in the said rod.

The ratchet-wheel A', having a feather, B', formed upon its bore, isplaced up on the drillstock in such a position as to engage the point ofthe pawl X; or, if found more convenient, the ratchet-wheel may beformed with such a bore as will it upon an octagonal drill, and thedrill-stock may be dispensed with.

At either side of vthe movable bed-plate standards C C' are placed, inwhich is j ournaled the shaft D', having keyed upon it the two triplecam-wheels or wiper-wheels E' F', and also the cog-wheel G', whichmeshes with the pinion H', keyed upon the shaft I', mounted in bearingsin the standards J' J', and driven by the crank-handle K', which may beplaced upon either end, or` one upon each end of the shaft I'. The cam-wheels or wipers are so set upon their driving-shaft that the points ofone cam-wheel will operate a little in advance of the points of theother cam-wheel.

Upon the face of the standard L is cast the lugs L', between which ispivoted the bellcrank M'. The upper end of said bellcrank enters theslot N', cut through the inner end of the rod T, and the opposite end isprovided with the adjustable friction-roller O', which engages with thecam-wheel F'.

The two lugs P' P are cast upon the upper face of the movable bed-plate,and between them is pivoted the bell-crank Q', one end of which entersthe slot R', cut through the lower end of the vertical rod W, and anadjustable friction-roller, S', is secured upon the opposite end of saidbell-crank and engages with the cam-wheel E'.

Upon the bed-plate B, and midway between the standards C C, I cast thelugs T' T', between which is pivoted the shank ofthe hammer U'. The faceof this hammer when it delivers a blow is in a vertical line with itspivotal point, and strikes the butt ofthe drill or drill-stock with astraight and direct blow. Upon one side of the shank is placed thefriction-roller V', which is acted upon by the calnwhecl F', and uponthe lower end of the hammershank is formed the tang W', upon the underside of which the upper free end of the doubled flat spring X' presses,as is seen in Fig. 1. The spring X' is let into a dovetailed groove cutin the upper surface of the bed plate B, and is held in position orprevented from working backward by the bar and bolt Y'. l

The operation of my improved rock-drilling machine will be as follows,to wit: The machine having been placed in position, with the point ofthe drill in contact with the face of the rock, the shaft D' is rotated,carrying with it the cams E' F'. The rounded faces of the cam-wheel F'are successively brought against the friction-roller V' of the hammer U'and force it backward, at the same time throwing the tang "W' downwardand compressing the spring X'. When the point of the cam passes beyondthe point at which contact with the friction-roller can be had, theexpansive power of the spring will cause the hammer-head to ily back toits original position and deliver a sudden and powerful blow upon theend of the drillstock. It should here be observed that as the fulcrum orpivotal point of the hammer is placed in a vertical line beneathl theface of the drill-stock the blow from the hammer will be given in anaxial line with the center of the drill-stock, and thereby impart itsfull force to the drill without any of the power being taken up by ashearing strain upon the journals in which the said drill or drill-stockis supported, as would be the case were the hammer to deliver a blowtangential to the axial line of the stock. The iirst blow having beendelivered, and the rotation of the shaft D' being continued, thesucceeding cam upon the right-hand cam or wiper wheel, F', will bebrought into contact with the friction-roller V' upon the hammer-shankand force the hammer backward, compressingthe spring X'. At the sametime the cam which last acted upon the hammer will, by pressing againstthe friction-roller O', cause the upper end of the bellcrank M' to bedrawn back, and at the same time draw back the rod T, and by means ofthe yoke S retract the drill from the face of the rock and compress thespring U. By the time this has beenl accomplished the cam of thewiper-wheel E' upon the left-hand side of the machine has come incontact with the friction-roller S' upon the bell-crank Q', causing theouter end thereof to move downward, carrying with it the rod NV,compressing the spring Z, and, by means of the ratchet-wheel A' and pawlX, will cause a partial rotation of the drill-stock I. As soon as thedrill has been rotated the cams of the wheel F' will be releasedfrom'contact with the bell-crank M' and friction-roller O', and theexpansion of the coiled spring U will move the drill into contact withthe face of the rock, and the cam of the wheel E', by passing out ofcontact with the bellcrank Q' and its friction-roller S', will permitthe coiled spring Z to throw the rod W up to its original position, asis shown in Fig. 2. These results having been accomplished, the hammerU', which was being gradually forced backward during the retraction,rotation, and advancement of the drill, is released from contact withthe cam-wheel F', and ilies forward and delivers another blow.

Having thus described my invention, what I claim, and desire to secureby Letters Patent,

l. In a rock-drilling machine, the combination of the drill-stock I,collars Q R, arranged thereon, horizontal rod T, provided with coiledIOO 3. In arock-drilling machine7 the combination of the shaft D',having cani-Wheel E', bell- 15 crank lever Q', having roller S', slottedrod WV, having springs Z Y and pawl X, the drill-stock I, having grooveJ, and the ratchet-Wheel A', having feather B', adapted to fit saidgroove, substantially as shown and described.

In testimony that I claim the foregoing I have 4hereunto set my hand andseal this 23d day of January, 1882.

THOMAS THRELFALL. [L s] IVitiiesses:

C. lV. M. SMITH, OHAs. E. KELLY.

